Numerous designs of propeller driven boats incorporating a tunnel in the boat hull have been developed. Such boats are typically categorized as shallow draft boats and the tunnels are utilized to direct the water toward the propeller driving the boat. Even though these designs provide water flow for the shallow draft design, in many instances they produce objectionable operating results. For example, in order for these prior art designs to provide sufficient water to the propeller, they create turbulent or resurgent water flow within the tunnel. Such turbulent or resurgent flow decreases the overall operating efficiency of the boat since it creates, in effect, a force which opposes the forward motion of the boat. It has also been found with these prior art designs that cavitation usually exists within the tunnel. Such cavitation can cause erosion of metallic objects, such as the propeller, which are exposed to same.
Because of the foregoing, it has become desirable to develop a tunnel design for a propeller driven boat wherein turbulent or resurgent water flow is negligible within the tunnel and wherein cavitation is minimized.